CFD analysis of WCLL BB PbLi manifold

ENEA CR Brasimone has developed the new design of the Water Cooled Lithium Lead Breeding Blanket(WCLL BB). In the new design Breeding Zone (BZ) water coolant flows in radial-toroidal direction, andPbLi flows in radial-poloidal direction; a gap between the Back Plate (BP) and the BZ constitutes the PbLiinlet manifold. The paper presents the CFD analysis of the WCLL BB PbLi inlet manifold, performed byANSYS CFX-15 code. The objective of the analysis is to investigate the PbLi flow paths in the manifoldregion and to optimize the mass flow rate distribution in the BZ of the module. A preliminary analyticalanalysis is performed to evaluate pressure drop at orifices and to select the diameter of the orifices.CFD simulations are performed with the selected geometries. The optimal geometric configuration is acompromise between the need to have low PbLi velocity, to limit MHD issues and Eurofer corrosion, andto preserve the structural capability of the stiffening plates to withstand the overpressure conditions.Results demonstrate that the layout of the manifold and the size of the orifices is suitable to uniformlydistribute the PbLi in the BZ, fulfilling the fluid velocity constraints. Specific MHD analyses are requiredto evaluate more realistic flow paths and to demonstrate the feasibility of the design.